L98 Valve Train Clatter
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
L98 Valve Train Clatter
My engine is nice and quiet whan cold, the first 5 minutes or so. When warm there is a lot of valve clatter. The valve lash is adjusted properly (zero lash plus 1/2 turn adjusted with engine running). What component is actually making the noise? Is there anything I can or should do?
Melting Slicks
Joined: Mar 2001
Posts: 3,365
Likes: 5
From: Lake Villa IL
Cruise-In IV Veteran
Cruise-In V Veteran
St. Jude Contributor
Re: L98 Valve Train Clatter (geezel)
How many miles are on your car? I had a valve clatter I could not remove. Turns out, I had a bad lifter. And a bad cam...
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 Valve Train Clatter (joeveto)
I've got 70k miles on the car plus new cam and lifters. It's not just a valve or two, the whole system appears to be noisy.
[Modified by geezel, 2:31 PM 3/11/2004]
[Modified by geezel, 2:31 PM 3/11/2004]
Racer
Joined: Jul 2000
Posts: 421
Likes: 0
From: Glen Burnie Md
Re: L98 Valve Train Clatter (geezel)
Geezel,
If I were you, I think I would have to revisit the valves, and make sure your adjustments are true.
Perhaps if you can give us the sequence you used to adjust the valves to begin with?
What grade of oil are you using? Same oil as before new cam and lifters added? How long ago was cam and lifters added? Usually, if valves are out of sequence, you can feel it in the pedal. Have you felt any lose of pedal response? What year Vette?
[Modified by UDLUV12, 6:17 PM 3/11/2004]
If I were you, I think I would have to revisit the valves, and make sure your adjustments are true.
Perhaps if you can give us the sequence you used to adjust the valves to begin with?
What grade of oil are you using? Same oil as before new cam and lifters added? How long ago was cam and lifters added? Usually, if valves are out of sequence, you can feel it in the pedal. Have you felt any lose of pedal response? What year Vette?
[Modified by UDLUV12, 6:17 PM 3/11/2004]
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 Valve Train Clatter (UDLUV12)
I tried several times with engine not runnig using generally accepted adjustment procedures. I think I always got them too tight due to trouble finding zero lash. Performance improved drastically after adjusting with engine running. Always the clatter no matter which method.
I,ve ran both 5W-30 and 10W-30 oil, doesn't seem to matter which.
I'm quite sure the cam & distruibuter are installed correctly and not part of the problem.
Throttle response is great. It's an '86.
I,ve ran both 5W-30 and 10W-30 oil, doesn't seem to matter which.
I'm quite sure the cam & distruibuter are installed correctly and not part of the problem.
Throttle response is great. It's an '86.
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 Valve Train Clatter (CFI-EFI)
Crane Gold 1.5 non self-aligning (I've got guide bars) New valve springs also per TPIS reccomendations when I purchased the cam from them. No head work.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: L98 Valve Train Clatter (geezel)
What are "guide bars"? Push rod guide plates? Where from? Stock iron heads? Any work done to the heads? I'm trying to help, here. I have an idea or two, but I need to know what you've put this together with.
RACE ON!!!
RACE ON!!!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Racer
Joined: Jul 2000
Posts: 421
Likes: 0
From: Glen Burnie Md
Re: L98 Valve Train Clatter (geezel)
Geezel,
It sounds as if you are doing all the right things. Has me stumped.
Perhaps a call to TPiS...since you got the cam and lifters from them.
They work on these combinations often, and should be able to offer a solution.
It sounds as if you are doing all the right things. Has me stumped.
Perhaps a call to TPiS...since you got the cam and lifters from them.
They work on these combinations often, and should be able to offer a solution.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: L98 Valve Train Clatter (geezel)
geezel IM'ed me and told me he is gone until Monday.
My concern was that he had more than one method of rocker arm alignment employed with this combination. It doesn't appear that way, now. Thsi IS puzzling. We'll work on it next week.
RACE ON!!!
My concern was that he had more than one method of rocker arm alignment employed with this combination. It doesn't appear that way, now. Thsi IS puzzling. We'll work on it next week.
RACE ON!!!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: L98 Valve Train Clatter (geezel)
We have pretty well hashed over the valve train and everything seems to be in order. Quiet cold. Noisy warmed up. Right? Is the cam and rocker arms the only thing you did in this operation? Your discription of the adjustment, sounds fine. What happens to the oil pressure between "quiet" and "noisy"? It seems as though you have a drastic drop in pressure, warmed up.
RACE ON!!!
PS. After it goes noisy and you shut it off. Is it quiet again, cold, until it re-warms up?
[Modified by CFI-EFI, 10:02 AM 3/15/2004]
RACE ON!!!
PS. After it goes noisy and you shut it off. Is it quiet again, cold, until it re-warms up?
[Modified by CFI-EFI, 10:02 AM 3/15/2004]
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 Valve Train Clatter (CFI-EFI)
I replaced lifters, springs and timing chain also (all TPIS stuff). It sure sounds like clatter is from above at rocker area, not lifters. Always quiet when cold. Noisy when warm or hot, even after shut-off & restart. I don't think oil pressure is an issue but I'll check in the next couple of hours.
Any chance the Crane roller rockers have gone south for some reason?
Any chance the Crane roller rockers have gone south for some reason?
Racer
Joined: Mar 2004
Posts: 311
Likes: 0
From: Oakley Ca
Re: L98 Valve Train Clatter (geezel)
Did you grind enough off? Something has to be "growing" a little bit with the heat causing the noise. I'd call TPIS and ask them too. Is it all the lifters or just one or two?
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 Valve Train Clatter (olman)
I believe most all the valves are contributing to the clatter. TPIS doesn't have any insights. They say if the oil pressur is good and the valves are adjusted properly, I'm good to go, it could just be the "nature of the set-up".
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: L98 Valve Train Clatter (geezel)
Light weight oil, like 10W30 contributes to valve train noise.
Valve train is quiet when oil is cold; telling me the oil viscosity is high and is quieting valve train noise.
Valve train becomes noisey when engine has warmed up; telling me oil viscosity is lower resulting in more noise.
The different between the two conditions is temperature affecting oil viscosity.
Try a load of 15W50 Mobil 1 or Pennzoil GT 20W50 or Valvoline VR1 20W50; you'll notice the diifference.
Jake
Valve train is quiet when oil is cold; telling me the oil viscosity is high and is quieting valve train noise.
Valve train becomes noisey when engine has warmed up; telling me oil viscosity is lower resulting in more noise.
The different between the two conditions is temperature affecting oil viscosity.
Try a load of 15W50 Mobil 1 or Pennzoil GT 20W50 or Valvoline VR1 20W50; you'll notice the diifference.
Jake
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
Re: L98 Valve Train Clatter (JAKE)
Probably a great idea. Is the higher viscosity oil ok whan the Owner's Manual reccomends 5W-30?
Oil pressure is good (I think) 60-65 PSI cold idle, 40-45 PSI warm idle, 54-55 PSI warm cruising.
[Modified by geezel, 5:24 PM 3/16/2004]
Oil pressure is good (I think) 60-65 PSI cold idle, 40-45 PSI warm idle, 54-55 PSI warm cruising.
[Modified by geezel, 5:24 PM 3/16/2004]
